Computer technologies continue to advance at a rapid pace. Indeed, computer technologies are involved in many aspects of a person's day. For example, many electronic devices being used today have a small computer incorporated within the device. These small computers come in varying sizes and degrees of sophistication. These small computers may vary in sophistication from one microcontroller to a fully-functional complete computer system. For example, small computers may be a one-chip computer, such as a microcontroller, a one-board type of computer, such as a controller, a typical desktop computer, such as an IBM-PC compatible, etc.
Electronic devices and computers typically have one or more processors at the heart of the device or computer. The processor(s) usually are interconnected to different external inputs and outputs and function to manage the particular computer or device. For example, a processor in a facsimile machine may be in electronic communication with buttons on the machine and with the scanning and printing components to enable faxes to be sent and received. By way of further example, a thermostat may be connected to buttons used to select the temperature setting, to the furnace or air conditioner to change the temperature, and to temperature sensors to read and display the current temperature on a display.
Many electronic devices include one or more small computers. For example, copiers, printers, facsimile machines, multi-function peripherals, thermostats, furnaces, air conditioning systems, refrigerators, telephones, typewriters, automobiles, vending machines, and many different types of industrial equipment now typically have small computers, or processors, inside of them. Computer software runs the processors of these computers and instructs the processors how to carry out certain tasks. For example, the computer software running on a thermostat may cause an air conditioner to stop running when a particular temperature is reached or may cause a heater to turn on when needed.
These types of small computers that are a part of a device, appliance, tool, etc., are often referred to as embedded systems. The term “embedded system” usually refers to computer hardware and software that is part of a larger system. Embedded systems may not have typical input and output devices such as a keyboard, mouse, and/or monitor, but they often have input and output devices such as keypads, buttons and smaller displays (such as an LCD). Usually, at the heart of each embedded system is one or more processor(s).
Embedded systems include and utilize non-volatile memory and volatile memory. Non-volatile memory is memory that holds its content without power. Examples of non-volatile memory are ROMs, PROMs, EPROMs, flash memory, hard drives, etc. Volatile memory loses its content without power. An example of volatile memory is RAM.
Typically at startup, embedded systems copy items from non-volatile memory to volatile memory or to RAM. Data stored in RAM may be accessed faster and thus improves performance of the embedded system. As a result, it is desirable to use RAM when possible. In certain cases RAM is not available for use because it is occupied by other program code or data. It would be beneficial to use RAM for its most efficient use and/or to reduce the RAM usage requirements of an embedded system. In addition, it would be beneficial to allow the RAM usage to be configurable.